It would be great if we could add friends in-game by sending them a request, possibly linked to a name link associated with the user. (This would be even better if no pre-requisites were required, such as having facebook, etc.) With this, players could challenge their friends to open a private room where thye can play 1v1, or where they can have multiple friends playing at once. The introduction of such a private room could also be simply hosted in some type of hub-world, where one could host a room protected by a password set by the user, enabling friends to play with each other among themselves.